Complete nucleotide sequence of the prophage VT2-Sakai carrying the verotoxin 2 genes of the enterohemorrhagic Escherichia coli O157:H7 derived from the Sakai outbreak

Kozo Makino, Katsushi Yokoyama, Yoshino Kubota, Chikako H. Yutsudo, Sigenobu Kimura, Ken Kurokawa, Kazuo Ishii, Masahiro Hattori, Ichiro Tatsuno, Hiroyuki Abe, Tetsuya Iida, Koichiro Yamamoto, Makoto Onishi, Tetsuya Hayashi, Teruo Yasunaga, Takeshi Honda, Chihiro Sasakawa, Hideo Shinagawa

研究成果: ジャーナルへの寄稿記事

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The enterohemorrhagic Escherichia coli (EHEC) 0157:H7 strain RIMD 0509952, derived from an outbreak in Sakai city, Japan, in 1996, produces two kinds of verotoxins, VT1 and VT2, encoded by the stx1 and stx2 genes. In the EHEC strains, as well as in other VT-producing E. coli strains, the toxins are encoded by lysogenic bacteriophages. The EHEC 0157:H7 strain RIMD 0509952 did not produce plaque-forming phage particles upon inducing treatments. We have determined the complete nucleotide sequence of a prophage, VT2-Sakai, carrying the stx2A and stx2B genes on the chromosome, and presumed the putative functions of the encoded proteins and the cis-acting DNA elements based on sequence homology data. To our surprise, the sequences in the regions of VT2-Sakai corresponding to the early gene regulators and replication proteins, and the DNA sequences recognized by the regulators share very limited homology to those of the VT2-encoding 933W phage carried by the EHEC 0157:H7 strain EDL933 reported by Plunkett et al. (J. Bacteriol., p1767-1778, 181, 1999), although the sequences corresponding to the structural components are almost identical. These data suggest that these two phages were derived from a common ancestral phage and that either or both of them underwent multiple genetic rearrangements. An IS629 insertion was found downstream of the stx2B gene and upstream of the lysis gene S, and this might be responsible for the absence of plaque-forming activity in the lysate obtained after inducing treatments.

ジャーナルGenes and Genetic Systems
出版物ステータス出版済み - 10 1 1999


All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Genetics